Hi there,
I see you are living in Cornwall. Why don't you give the Culdrose public relations officer a call and ask about going in there for the day and actually talk to some of the people of those ranks either Engineers or Aircrew.
Depending on your particular trade there are obviously different levels of responsibility for each rank in question and there is a direct relationship to how inportant that partucular trad is in the big scheme of things. For example you can have a;
Petty Officer Steward. He makes sure that the officers mess is up to scratch If he messe up no big deal as the officer misses out on a cup of tea which he is capable of making himself anyway.
Petty Officer Aircraft Engineer. Now if he makes a mistake people can die
You see what I mean. They are both the same Rank but their responsibilities and consequences of their actions are worlds apart.
Then you have NCO Aircrew who are at the top of the NCO Food chain (Lol).
Hope this helps but seriously give Culdrose a call if you want to see for yourself as they entertain students all the time especially if you are thinking of joining. PM if you want any more info